When we think about rheumatoid arthritis (RA), the first thing that comes to mind is inflammation. But a recent study has challenged this traditional view, revealing that less than half (46%) of RA patients with moderate to severe disease activity actually had active inflammation confirmed by ultrasound. This discovery shifts the conversation from focusing solely on inflammation to considering alternative sources of pain, such as fibromyalgia (FM) and nociplastic pain.

So, what does this mean for patients and their care? Let’s dive into the details.

The Overlap of Fibromyalgia and RA

Published in Rheumatic & Musculoskeletal Diseases Open, the study explores how RA-related pain may go beyond inflammation. For many patients, symptoms like persistent pain, fatigue, and mood disturbances may actually stem from fibromyalgia—a condition characterized by widespread pain not linked to inflammation.

The research team set out to better understand the nature of RA-related pain by assessing 158 patients with moderate to high disease activity. Using ultrasound imaging, they categorized patients into four distinct groups based on the presence or absence of FM and inflammation:

1. 27.2% had no fibromyalgia or signs of inflammation.

2. 27.2% had no fibromyalgia but showed signs of inflammation.

3. 26.6% had fibromyalgia but no signs of inflammation.

4. 19% had both fibromyalgia and inflammation.

Interestingly, patients with fibromyalgia consistently reported worse outcomes in terms of pain, mood, and fatigue, regardless of whether inflammation was present.

The Role of Peripheral Nociplastic Pain

One of the most surprising findings was the discovery of peripheral nociplastic pain in about 27% of patients who had neither inflammation nor fibromyalgia. This type of pain, which arises from changes in the way the nervous system processes pain signals, has only recently been recognized in rheumatology.

In these patients, their symptoms could not be explained by traditional inflammatory pathways. Instead, the pain seems to be driven by altered sensory processing—a phenomenon often overlooked in the management of RA.

Why This Matters for RA Treatment

These findings highlight an important reality: not all RA pain is caused by inflammation. For years, treatments for RA have focused on targeting inflammation with medications like disease-modifying antirheumatic drugs (DMARDs). While these therapies are effective for many, they may not address the full scope of pain experienced by some patients.

The recognition of peripheral nociplastic pain could pave the way for more personalized treatment approaches. For example, therapies targeting the nervous system or addressing central pain mechanisms might be more beneficial for this subgroup of patients.

Challenges and the Road Ahead

The study, while groundbreaking, had its limitations. The small sample size and reliance on older fibromyalgia diagnostic criteria (from 2010) mean that more research is needed to confirm and expand upon these findings. Additionally, developing tools to identify and categorize these distinct pain mechanisms will be crucial for advancing patient care.

The researchers concluded that further studies using advanced imaging and pain sensitization methods could shed light on the complexities of RA-related pain.

A Call to Action

For patients with RA, this research offers hope. It validates the experiences of those whose pain persists despite inflammation being under control and opens the door to new treatment possibilities.

At the American Arthritis Foundation, we are committed to raising awareness of these findings and advocating for research that leads to better outcomes for RA patients. Understanding pain in all its forms—whether inflammatory, nociplastic, or fibromyalgic—is key to improving quality of life.

Have you or someone you know experienced RA pain that doesn’t seem to fit the usual patterns? Share your story or connect with us to learn more about emerging therapies and support. Together, we can push the boundaries of what’s possible in arthritis care.